Virtual colonoscopy (VC) is an effective medical procedure for use in identifying polyps and cancers in the bowel. Typically, an oral laxative is administered to a patient to cleanse and empty the bowel of solid stool. Once the bowel is cleansed, the colon is insufflated with gas. After the colon is distended by the gas, the patient's abdomen and pelvis are scanned using a selected scan procedure, such as computed tomography (CT) or magnetic resonance imaging (MRI), while the patient lies motionless during a breath hold. Finally, image analysis is performed by a physician and/or computer-aided diagnosis to diagnose polyps, cancer or other abnormalities in the bowel.
Colonic insufflation usually involves administering air or other selected gas into a patient's colon through a rectal catheter. A technologist monitors the flow of gas through the rectal catheter into the colon. Once the technologist believes that the colon has been sufficiently insufflated the patient's abdomen and pelvis are scanned.
Subjective determination of colon distention during a VC procedure has several drawbacks. For example, false readings may be obtained if the colon is not properly distended throughout the CT or MRI scan. An improperly distended colon, or a colon affected by contractions (including normal peristalsis and spasms) may produce misleading images and errors in diagnosis because of the potential of collapsed bowel segments mimicking or masking true lesions. Furthermore, patient intolerance to colonic distention can lead to patient motion, either respiratory or body movements, during the scan which can also produce image artifacts that lead to incorrect diagnoses.
Accordingly, an apparatus for objectively determining distention of the colon and relative patient sensations, hence improving the accuracy of a medical procedure such as a VC scan, and for use as a diagnostic test, is desirable.